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The introduction to Reactive Programming you've been missing

(by @andrestaltz)

So you're curious in learning this new thing called (Functional) Reactive Programming (FRP).

Learning it is hard, even harder by the lack of good material. When I started, I tried looking for tutorials. I found only a handful of practical guides, but they just scratched the surface and never tackled the challenge of building the whole architecture around it. Library documentations often don't help when you're trying to understand some function. I mean, honestly, look at this:

Rx.Observable.prototype.flatMapLatest(selector, [thisArg])

Projects each element of an observable sequence into a new sequence of observable sequences by incorporating the element's index and then transforms an observable sequence of observable sequences into an observable sequence producing values only from the most recent observable sequence.

Java to Dart

This is an ad-hoc Java-to-Dart translator originally written on two (admittedly long) evenings.

See http://sma.github.io/stuff/java2dartweb/java2dartweb.html for a demo.

Note: It doesn't support the complete Java grammar specification and cannot translate everything. It only translates syntax and does not attempt to translate Java library classes and methods to Dart equivalents (with the exception of String.charAt and StringBuffer.append). You will have to make changes to the resulting Dart code. It does not support anonymous inner classes.

However, I was able to successfully convert a 7000+ line command line application with only minimal fixes in 30 minutes.

	package enum_example

	import (
	"bytes"
	"encoding/json"
	)

	// TaskState represents the state of task, moving through Created, Running then Finished or Errorred
	type TaskState int

	-- show running queries (pre 9.2)
	SELECT procpid, age(clock_timestamp(), query_start), usename, current_query
	FROM pg_stat_activity
	WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%'
	ORDER BY query_start desc;

	-- show running queries (9.2)
	SELECT pid, age(clock_timestamp(), query_start), usename, query
	FROM pg_stat_activity
	WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%'

	max_connections = 1500 # (change requires restart)
	shared_buffers = 12000MB # min 128kB, based on 80GB RAM DB
	temp_buffers = 8MB # min 800kB
	work_mem = 64MB # min 64kB
	maintenance_work_mem = 512MB # min 1MB

	wal_level = hot_standby # minimal, archive, or hot_standby
	checkpoint_segments = 64 # in logfile segments, min 1, 16MB each
	checkpoint_completion_target = 0.9 # checkpoint target duration, 0.0 - 1.0
	max_wal_senders = 6 # max number of walsender processes

	#!/usr/bin/env bash

	# Pre-requisites
	sudo apt-get -y update
	sudo apt-get --no-install-recommends -y install build-essential openssl libreadline6 libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libsqlite3-dev sqlite3 libxml2-dev libxslt-dev autoconf libc6-dev libgdbm-dev ncurses-dev automake libtool bison subversion pkg-config libffi-dev vim

	# Download and compile Ruby 2.0.0-p0
	cd /tmp
	wget ftp://ftp.ruby-lang.org/pub/ruby/2.0/ruby-2.0.0-p0.tar.gz
	tar -xvzf ruby-2.0.0-p0.tar.gz

	var parser = document.createElement('a');
	parser.href = "http://example.com:3000/pathname/?search=test#hash";

	parser.protocol; // => "http:"
	parser.hostname; // => "example.com"
	parser.port; // => "3000"
	parser.pathname; // => "/pathname/"
	parser.search; // => "?search=test"
	parser.hash; // => "#hash"
	parser.host; // => "example.com:3000"

	# to generate your dhparam.pem file, run in the terminal
	openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048

	//
	// _oo0oo_
	// o8888888o
	// 88" . "88
	// (\| -_- \|)
	// 0\ = /0
	// ___/`---'\___
	// .' \\\| \|// '.
	// / \\\|\|\| : \|\|\|// \
	// / _\|\|\|\|\| -:- \|\|\|\|\|- \